Falkus
Explorer
I think that if Haley knew it was Nale and really wanted to get it across, she'd just go find something to write with and give Roy a note explaining the situation. Or maybe that's too easy; I don't know.
Aphasia isn't just an inability to speak properly, it's an inability to produce and/or comprehend languages, both spoken and written. I'd say that Haley's suffering from Transcortical Motor Aphasia, in which she has impaired speech and writing abilities, but full comprehension.
Ah, gotta love wikipedia.